Technical Field
Embodiments disclosed herein are related to improved visualization for vitreo-retinal, glaucoma, or other ophthalmic surgeries. More specifically, embodiments described herein relate to a movable wide-angle ophthalmic surgical system that can be implemented as a diagnostic imaging system and/or a treatment beam delivery system.
Related Art
Developing techniques to assist ophthalmic surgery with imaging and visualization is one of the hottest areas of development and innovation. One class of ophthalmic surgeries, the vitreo-retinal procedure, involves vitrectomy, the removal of the vitreous body from the posterior chamber to access the retina. The successful execution of vitrectomy requires an essentially complete removal of the vitreous, including the most challenging regions near the vitreous base. Using imaging techniques and devices can be of substantial help to improve the efficiency of the vitreous removal.
However, assisting vitrectomy with imaging is particularly challenging for several reasons. One of them is that the vitreous is transparent. Another challenge is that visualization of the periphery requires imaging beams with a high angle of obliqueness. Wide angle contact-based or non-contact based lenses are commonly used to address the latter challenge, with only limited success. There are many other reasons that surgeons need to have a wider field of view into the eye in vitreoretinal surgeries, such as for retinal break detection, photocoagulation, etc. Wide-angle contact based lenses can reach approximately 120° field of view, while non-contact based lenses offer an even narrower field of view. Sometimes, surgeons have to rotate the patient's eyeball or perform sclera depression to move the eye into the microscope field of view for observation.
Improvement of the imaging can be achieved by using optical coherence tomography (OCT), a technique that enables visualization of the target tissue in depth by focusing a laser beam onto the target, collecting the reflected beam, interfering the reflected beam with a reference beam and detecting the interference, and measuring the reflectance signature within the depth of focus of the beam. The result is a line scan in depth, a cross-sectional scan, or a volumetric scan.
OCT has become common practice in the clinic as a diagnostic tool. Surgeons take pre-op images into the operating room for reference. OCT scanning is currently not available in the operating room, and thus does not support decision making during surgery. Pre-op images have limited utility following morphologic modifications to the target during a procedure.
Efforts to develop real-time intra-surgical OCT systems are being made by multiple companies ranging from startups to large corporations. The approaches to intra-surgical OCT to date have been microscope-based, handheld probe-based, or endoprobe-based. Microscope-based OCT systems have conventionally mounted the OCT system to the microscope with a fixed orientation with respect to the microscope and/or a patient's eye. Accordingly, integrating OCT into standard surgical microscopes can require substantial modifications of the microscope. Further, even with these modifications, the scanning angle and/or the target location of the OCT beam into the eye is fixed and limited. Moving the patient and/or microscope, both of which can be impractical or infeasible, are the only options for change the scanning angle and/or the target location of the OCT beam.